Shotgun choke



L. M. DENAUX SHOTGUN CHOKE July 24, 1962 2 Sheets-Sheet 1 Filed July 27, 1960 Louis M Denaux INVENTOR.

L. M. DENAUX SHOTGUN CHOKE July 24, 1962 Filed July 27, 1960 2 Sheets-Sheet 2 Louis M. Denaux I INVENTOR.

1 BY M WWW/0y 3m United States Patent 3,045,378 SHOTGUN CHOKE Louis M. Denaux, Cosgrove Ave., 2.0. Box 3258,

Charleston, S.C. Filed July27, 1960, Ser. No. 45,687 4 Claims. (Cl. 42-79) This invention relates to a gas operated, spring rotated, automatic choke for shotguns, and more particularly to an automatic choke capable of progressively choking the barrel of a shotgun each time the gun is fired.

Shotgun chokes are utilized to restrict the cross-sectional area of the muzzle end of the shotgun so that a shot pattern of a given dimension may be maintained at progressively greater distances from the shotgun. Being able to maintain a shot pattern of a given dimension at various distances from the gun enables a hunter to fire a predetermined shot pattern at a given distance. When hunting duck and similar game likely to take flight after the first firing of a gun, the most desirable type of shotgun choke is that type of choke which will, each time the shotgun is fired, increase the choke effect on the pattern of shot thereby enabling the same diameter shot pattern to be maintained at progressively increasing distance from the gun. With this type of automatic choke a shot pattern of a given diameter may be maintained at the distance at which the game is from the shotgun during the flight of the game away from the shotgun.

The main object of this invention is to provide an automatic choke for shotguns which 'will, each time the shotgun is fired, progressively choke the muzzle of the shotgun so that a shot pattern of a given diameter may be maintained at distances progressively further from the shotgun.

A further object of this invention, in accordance with the immediately preceding object, is to provide an automatic choke including movable means defining a bore aligned with the barrel of a shotgun and an actuator movably mounted for oscillating movement and engaging the movable bore defining means for effecting movement of the latter to constrict the bore formed thereby upon movement of the actuator in one direction with means being provided for urging the actuator in that direction and releasable latch means connected with the actuator for retaining the latter in position against movement in that direction.

A further object of this invention is to provide latch means including a plurality of stops arranged in the direction of movement of the actuator of the shot gun selectively engageable by the actuating means of the shotgun choke whereby the shotgun choke may be adjusted to provide the desired amount of constriction of the bore defined by the shotgun choke.

Still another object of this invention, in accordance with the immediately preceding object, is to provide the latch means with pressure sensitive means for releasing the latch means and means for communicating the interior of a shotgun barrel with the latch means whereby the pressure Within the :barrel each time the shotgun is fired will release the latch means and enable the actuator to move to the next position.

A final object to be specifically enumerated herein is to provide a shotgun choke which will conform to conventional forms of manufacture, be of simple construction and easy to operate so as to provide a device that will be economically feasible, long lasting and simple in operation.

These together with other objects and advantages which will become subsequently apparent reside'in the details of construction and operation as more fully hereinafter described and claimed, reference being had to the accomm I C6 panying drawings forming a part hereof, wherein like numerals refer to like parts throughout, and in which:

FIGURE 1 is a side elevational view of the muzzle end of a shotgun shown with the choke of the instant invention mounted thereon;

FIGURE 2 is a side elevational view similar to that of FIGURE 1 but shown with the outer sleeve of the shotgun choke removed;

FIGURE 3 is a still further side elevational view similar to FIGURE 1 but with the outer sleeve and the actuator spring removed;

FIGURE 4 is yet another side elevational view similar to FIGURE 1 but showing the outer sleeve, the actuator spring and the collet sleeve removed;

FIGURE 5 is an enlarged vertical longitudinal sectional view taken substantially upon a plane passing along the longitudinal center line of the shotgun barrel;

vFIGURE 6 is a transverse vertical sectional view taken substantially upon the plane indicated by the section line 6--6 of FIGURE 5;

FIGURE 7 is a transverse vertical'sectional view taken substantially upon the plane indicated by the section line 7-7 of FIGURE 5;

FIGURES 8 and9 are fragmentary vertical sectional views taken substantially upon the plane indicated by the section line 7-7 of FIGURE 5 and showing the choke assembly in difierent positions of operation;

FIGURE 10 is an exploded perspective view of the shotgun choke and the muzzle end of the shotgun barrel.

Referring now more specifically to the drawings, the numeral 10 generally designates the muzzle end of a shotgun barrel on which there is secured an automatic gas operated choke generally designated by the reference numeral 12.

The muzzle end of the shotgun barrel has a pair of circumferentially extending grooves 14 and 16 formed therein and a transverse internally threaded bore 18 is formed I ,tion and disposed about the muzzle end of the barrel 10 with the circumferentially extending ridge 28 formed between the grooves 14 and 16 having portions thereof received within the arcuate grooves 30 formed in the inner faces of the fingers 26. The rear or inner ends of the fingers 26 are reduced as at 32 and a compression spring ring 34 is disposed about the reduced ends 32 of the tin gets 26. With'attention directed more particularly to FIGURE 5 of the drawings it will be noted that the ridge '28 more or less forms a pivot point for each of the fingers 26 with the spring 34 normally urging the forward a or outer ends of the fingers 26 apart. The inner surfaces of the fingers 26 define a bore 36 aligned with the bore 38 in the barrel 10 and actuator means in the form of an actuator sleeve generally designated by the reference numeral 40 is disposed over the muzzle end of the shotgun barrel 10 and the fingers 26.

The inner surfaces of the sleeve 40 are forwardly convergent as at 42. These inwardly convergent surfaces 42 engage the bevelled surfaces 44 on the forward ends of the fingers 26 upon rearward movement of the sleeve 40 to urge the forward ends of the fingers 26: inwardly against the tension of the spring 34 whereby the fingers 26 comprise means for constricting the bore 36.

The sleeve 40 is provided with a spiral slot 46 in which the guide block 20 is disposed so that rotation of the sleeve 40 relative to the barrel 10 will also eifect longitudinal movement of the sleeve 40 relative to the barrel 10. Therefore, upon rotating movement of the sleeve 40 relative to the barrel 10, the forward ends of the fingers 26 may be moved either toward or away from each other depending upon the direction of rotation of the sleeve 40.

A coiled torsion spring 48 is disposed about the sleeve 4-0 and has one angulated inwardly directed end portion 50 removably seated in an aperture 52 formed on the sleeve 40 and a second angulated end portion 54 seated within the slot 56 in the guide block 20 by means of the head 58 of the fastener 22. Thus, inasmuch as one end of the spring 48 is secured to the barrel and the other end is secured to the sleeve 40, the sleeve 40 is resiliently urged toward rotation in one direction relative to the barrel 10. It will be noted that the spring 48 resiliently urges the sleeve 40 in a counterclockwise direction as viewed in FIGURE 10 thus effecting longitudinal movement of the sleeve 40 in a direction to compressively engage and inwardly deflect the forward ends of the fingers 26 thus constricting the bore 36.

The rear end of the sleeve 40 is provided with an in ternal circumferentially extending groove 60 in which there is seated an arcuate leaf spring generally designated by the reference numeral 62. One end of the leaf spring 62 is provided with an outwardly directed retaining tab 64 which is seated in the slot 66 formed in the rear end of the sleeve 40 and the other end of the spring 62 is provided with an inwardly angulated latch end portion 68 successively engageable with one of the plurality of circumferentially extending and spaced notches 70 formed in the barrel 10 which notches coact with the leaf spring 62 to form latch means for retaining said sleeve in adjusted rotated positions.

With particular attention now directed to FIGURES 7 through 9 of the drawings, it will be noted that each of the notches or stops 70 is provided with an inwardly inclined approach end wall 72 and a substantially radially extending departure wall 74. A plurality of passages 76 are formed in the barrel 10 and communicate the bore 38 with the bottom of the notches 70.

The sleeve 40 is also provided with an internally threaded transverse bore 78 in which there is threadedly engaged a stop screw 80 having a stepped inner end 82 selectively engageable with the free end portion of the inwardly angulated latch end portion 68 of the leaf spring 62 upon rotation of the screw 80 to maintain the latch end portion 68 seated within the associated notch 70.

Although the barrel 10 has been illustrated as provided with the grooves 14- and 16 as well as the ridge 28, the bore 18 and the notches 70 and their passages 76, it is to be noted that these structural features of the invention may be conveniently incorporated in a mounting sleeve adapted to be fixedly secured to the muzzle end of a shotgun barrel whereby it will not be necessary to machine the shotgun barrel other than to provide a means for retaining the mounting sleeve in position thereon and to provide suitable openings communicating the interior of the barrel with the passages 76.

In operation, the sleeve 40 may be first manually rotated in a counterclockwise direction as viewed from the muzzle end of the barrel 10 to seat the latch end portion 68 of the spring 62 in one of the notches 70 as illustrated in FIGURE 7 of the drawings. Movement of the sleeve 40 to the position illustrated in FIGURE 7 of the drawings will enable the spring 34 to urge the forward ends of the fingers 26 apart whereby the shotgun choke 12 will be fully opened.

Upon the firing of the gun of which the barrel 10 comprises a part the pressure within the barrel 10 will be communicated to the latch end portion 68 of the spring 62 by means of the adjacent passage 76 whereby the end portion 68 comprising pressure responsive release means will be urged outwardly and moved from seating engagement with that notch 70. After the end portion 68 has been urged outwardly, the spring 48 will rotate the sleeve 40 in a clockwise direction until the end portion 68 is registered with the next notch 70 and seated in engage ment with its departure end wall 74. This action will restrict further clockwise rotation of the sleeve 40 to further choke the barrel 10 until the gun is again fired whereupon the sleeve will again be rotated in a clockwise direction by means of the spring 48 to the fully choked position with the guide block 20 engaged with one end of the slot 46.

If it is desired to limit the amount the attachment can choke the barrel 10, the screw may be rotated from the position illustrated in FIGURES 7 through 9 to prevent the end portion 68 from moving outwardly out of seated engagement with the associated departure end wall 74 after it has once been engaged therewith.

The sleeve 40 is provided with a radially extending flange 84 on its rear end and an outer protective sleeve 86 is disposed about the actuator sleeve 40 and the spring 48.

As it is, the shotgun choke 12 is constructed of relatively few parts and if the fingers 26 were formed as a unit, the number of actual working parts of the choke 12 would be reduced to six which is considerably less than the number of parts utilized in the construction of even inferior shotgun chokes now on the market.

The foregoing is considered as illustrative only of the principles of the invention. Further, since numerous modifications and changes will readily occur to those skilled in the art, it is not desired to limit the invention to the exact construction and operation shown and described, and accordingly all suitable modifications and equivalents may be resorted to, falling within the scope of the invention as claimed.

What is claimed as new is as follows:

1. In combination, a gun barrel, a choke assembly, said choke assembly including an actuator, means mounting said actuator on said barrel for oscillating movement relative thereto, said choke assembly including movable means defining a bore aligned with said barrel, said actuator engaging said movable bore defining means for effecting movement of the latter to constrict said bore upon movement of said actuator in one direction, means resiliently urging said actuator in said one direction and releasable latch means connected between said actuator and said barrel retaining said actuator in position against movement in said one direction, said latch means including pressure responsive means for releasing said latch means, and means communicating said pressure responsive means with the interior of said barrel, said latch means including a plurality of successively engageable stops formed in said gun barrel, said stops comprising a plurality of notches formed in said barrel and extending in the direction of travel of said actuator and having an inwardly inclined approach end wall and a substantially radially extending departure wall, a resilient leaf spring having one end secured to said actuator and the other end projecting in the direction of movement of said actuator and provided with a normally inwardly angled latch end portion successively engageable with said departure walls, said actuator comprising a sleeve rotatably mounted on said barrel, said notches being disposed circumferentially about said barrel and said leaf spring being arcuate and extending circumferentially about said barrel, said sleeve including means for moving said bore defining means to constrict said bore upon displacement of said sleeve longitudinally of said barrel, said barrel and said sleeve including coacting means effecting displacement of said sleeve longitudinally of said barrel upon rotation of said sleeve relative to said barrel, said coacting displacement effecting means including a radially and outwardly projecting guide block carried by said barrel, and a helical slot formed in said sleeve slidably receiving said guide block.

2. The combination of claim 1 wherein said resilient urging means is secured between said guide block and said sleeve, means removably securing said guide block to said barrel whereby the entire choke assembly is secured on said barrel by means of said guide block.

liders l 3. In combination, a gun barrel, a choke assembly, said choke assembly including an actuator, means mounting said actuatorpon said barrel for oscillating movement relative thereto, said choke assembly including movable means defining a bore aligned with said barrel, said actuator engaging said movable bore defining means for efieeting movement of the latter to constrict said bore upon movement of said actuator in one direction, means sleeve including coasting means efiecting displacement of said sleeve longitudinally (if said barrel upon rotation of said sleeve relative to said barrel, said coacting displacement effecting means including a radially and outwardly projecting guide block carried by said barrel, and a helical slot formed in said sleeve slidably receiving said guide block.

4. The combination of claim '3 wherein said barrel has a circumferentially extending ridge formed on its muzzle end defined by a circumferentially extending 6 grooves formed in said bar-rel a spaced distance longitudinally of said barrel from said muzzle end, said movable bore defining means comprising a plurality of elongated collet fingers extending longitudinally of and disposed circumferentially about said muzzle end of said barrel, each of said collet fingers, at one end, projecting longitudinally beyond the muzzle end of said barrel, said fingers each being generally arcuate in cross-section and having a transverse 'arcuate groove formed therein a spaced distance from the other end thereof, said arcuate grooves receiving corresponding portions of said ridge, said other ends of said fingers being received in said circumferential groove, a compression spring ring disposed about and normally yieldably urgingsaid other ends of said fingers radially inwardly of said barrel and toward positions seated in said circumferential groove, said sleeve being telescoped over said fingers and including inwardly beveled inner surfaces extending circumferentially about the outer end thereof engageable with said one end of said fingers upon rearward displacement of said sleeve on said barrel for radially inwardly deflecting said one end of said fingers to constrict the bore defined thereby.

References Cited in the file of this patent Hare June 27, 1961 

